Biological Molecules

Biological Molecules

• Biological molecules are the vital substances found in living organisms, helping in growth, development, and functioning of life processes.

Carbohydrates

• Carbohydrates are essential biological molecules that majorly serve as an energy source.
• Chemically, they are comprised of carbon, hydrogen, and oxygen.
• They can be simple, including monosaccharides like glucose, or complex, such as polysaccharides like starch.

Lipids

• Lipids are biological molecules which are hydrophobic or insoluble in water.
• They include fats, oils, and cholesterol.
• Lipids play important roles in long-term energy storage, insulation, and cell membrane formation.

Proteins

• Proteins are large biological molecules made up of one or more chains of amino acids.
• These are required for the structure, function, and regulation of body’s tissues and organs.
• Proteins, such as enzymes and antibodies, perform a vast array of functions within organisms.

Nucleic Acids

• Nucleic acids, such as DNA and RNA, are complex organic substances present in living cells.
• They are responsible for the storage, transmission, and execution of genetic information.
• DNA is the molecule that holds the instructions for all living things, while RNA is involved in protein synthesis.

Testing for Biological Molecules

• Biological molecule tests help in determining the presence of specific molecules in a sample.
• A positive starch test will turn the iodine solution blue-black.
• Benedict’s test for reducing sugars results in a color change from blue to green, yellow, or brick-red on heating.
• The biuret test for proteins turns the solution lilac or purple.
• The paper test for lipids leaves a translucent spot on the paper.